
    import java.util.Scanner;

    //斐波那契数列
    public class T1 {
        public static void main(String[] args) {
            Scanner scan = new Scanner(System.in);
            int n = scan.nextInt();
            System.out.print(f(n));
        }

        public static long f(int n) {
            //边界
            if(n==1||n==2) {
                return 1;
            }
            //重复
            long ret = f(n-1)+f(n-2);
            //写在这里并不会进行多次取模运算，而是上面都计算完才会进行最后一步取模运算
            ret %= (long)1e9+7;
            return ret;
        }
    }


